There and Back Again has exactly two lore counters on it.
Umbral Mantle attached to Satsuki.
Satsuki does not have summoning sickness.
({1} magic symbol) ({BP} magic symbol) , plus an additional ({5} magic symbol) ({BP} magic symbol) available if you do not control a Smaug token available.
Steps
Activate Satsuki by tapping it, putting a lore counter on There and Back Again.
There and Back Again's third chapter ability triggers.
Holding priority, activate Hex Parasite by paying ({1} magic symbol) ({BP} magic symbol) , removing a lore counter from There and Back Again and giving Hex Parasite +1/+0 until end of turn.
Resolve the There and Back Again ability, creating a legendary 6/6 Smaug creature token.
If you control two Smaugs, put one into your graveyard due to the legend rule.
If you do, the Smaug that died triggers, creating fourteen Treasure tokens.
If you made Treasures this way, activate six Treasures by tapping and sacrificing them, adding ({5} magic symbol) ({B} magic symbol) .
Activate Staff of Domination's third ability by paying ({3} magic symbol) and tapping it, untapping Satsuki.
Activate Staff of Domination's first ability by paying ({1} magic symbol) , untapping it.
Repeat.
Once you have infinite mana, you may use it to activate Staff of Domination's other abilities.
Results
Infinite card draw.
Infinite colored mana.
Infinite death triggers.
Infinite draw triggers.
Infinite ETB.
Infinite lifegain.
Infinite lifegain triggers.
Infinite LTB.
Infinitely powerful Hex Parasite until end of turn.